Church officials and historians in Fulham are split over building plans that would see gravestones moved and a tomb destroyed.
All Saints Church wants to build an annex on its site off Putney Bridge Approach, a plot designated as Metropolitan Open Land.
Gravestones would be removed and the tomb of botanist William John Burchell would have to be demolished and his remains disinterred.
The 83-year-old chairman of the Fulham Society, John Robb, said: "I think the footprint of it would be almost as big as the church itself. It is pretty big and it would be built over the graveyard."
Vice president John Putnam, 73, from Ranelagh Gardens, Fulham, said development on Metropolitan Open Land is highly restricted.
He added: "Camden Council recently granted planning permission for building on Metropolitan Open Land, but that was quashed by the High Court.
"We have alerted Hammersmith and Fulham Council about this. We are also very concerned about William Burchell's tomb.
"Personally, I am very uneasy about the idea of building over human remains."
All Saints' vicar Joe Hawes is also a member of the Society and claims the graveyard would be 'unaffected'. He said: "We are using modern techniques to ensure we do not disturb human remains.
"Lots of my congregation are members of the Fulham Society. I have addressed two of its annual meetings and would question how representative this objection is of views of members."
Mr Hawes said Sunday services attract more than 600 people and added: "We have inadequate facilities, one primitive loo and no teaching space for more than 150 kids. We're proposing a modest one-storey building, made from natural materials."
The gravestones may be used as flooring in a glass walkway between the church and annex.
All Saints has applied to Hammersmith and Fulham Council for planning permission and is waiting for a response.